Heat Exchanger

Abstract

A heat exchanger comprises a stack of mutually spaced apart plates. The plates are separated by respective spacings therebetween. Alternate spacings respectively provide a flow path for a first fluid and a second fluid. The heat exchanger further comprises a first header for inflow of the first fluid and a second header for outflow of the first fluid. The first and second headers are connected to the plate stack by flexible tubular ducting means.

1 . A heat exchanger comprising a stack of mutually spaced apart plates separated by respective spacings therebetween, wherein alternate spacings respectively provide a flow path for a first fluid and a second fluid, the heat exchanger further comprising a first header for inflow of the first fluid and a second header for outflow of the first fluid, wherein respective cells are formed by pairs of the plates, the spacing between which constitutes all or part of the first fluid flow path, the first and second headers being connected to the plate stack by flexible tubular ducting means such that respective pairs or groups of flexible ducting means connect each cell with a particular header.  
   
   
       2 . The heat exchanger of  claim 1 , wherein respective pairs of flexible ducting means connect each cell with a particular header and the shapes in each pair are symmetrical about an axis of symmetry.  
   
   
       3 . The heat exchanger of  claim 2 , wherein the axis of symmetry is substantially parallel to the direction of fluid flow in the first fluid flow path.  
   
   
       4 . The heat exchanger of  claim 1 , wherein the flexible tubular ducting means comprises respective tubes communicating between the spacings representing the first fluid flow path and the insides of the first and second headers.  
   
   
       5 . The heat exchanger of  claim 4 , wherein the tubes are flexible by virtue of being arranged to follow a tortuous path.  
   
   
       6 . The heat exchanger of  claim 5 , wherein the tortuous path comprises a curved portion.  
   
   
       7 . The heat exchanger of  claim 5 , wherein the tortuous path comprises a portion having at least one helical turn.  
   
   
       8 . The heat exchanger of  claim 5 , wherein the tortuous path comprises at least one angled region.  
   
   
       9 . The heat exchanger of  claim 4 , wherein the tubes are flexible by virtue of the material from which they are made.  
   
   
       10 . The heat exchanger of  claim 5 , wherein the tubes are flexible by virtue of their overall lengths.  
   
   
       11 . The heat exchanger of  claim 5 , wherein the plates have two opposite sides substantially parallel to the direction of the first fluid flow path and are joined respectively by two connecting sides at each end of the first fluid flow path.  
   
   
       12 . The heat exchanger of  claim 11 , wherein the tubes at one or both ends of the first fluid flow path communicate with the said spacings defining the fluid flow path at one or both of the two opposite sides substantially parallel to the direction of the first fluid flow path.  
   
   
       13 . The heat exchanger of  claim 11 , wherein the tubes at one or both ends of the first fluid flow path communicate with the spacings defining the first fluid flow path respectively at one or both connecting sides.  
   
   
       14 . The heat exchanger of  claim 13 , wherein the tubes communicating with one or both connecting sides do so via a common duct.  
   
   
       15 . The heat exchanger of  claim 4 , wherein the mean hydraulic diameter of each tube is from 0.5 to 2 times the average plate-to-plate distance of the spacings representing the first fluid flow path.  
   
   
       16 . The heat exchanger of  claim 4 , wherein the average length of the tubes is from 0.1 to 2 times the width of the plates normal to the flow direction of the first fluid flow path.  
   
   
       17 . The heat exchanger of  claim 1 , wherein the ducting means is arranged to direct inflow of the first fluid to the spacings defining the first fluid flow path in a direction from 90° to 30° relative to the direction of flow in the first fluid flow path.  
   
   
       18 . The heat exchanger of  claim 17 , wherein inflow diversion means is located at or near the entry region of the spacings defining the first fluid flow path to enhance uniformity of flow in said fluid flow path.  
   
   
       19 . The heat exchanger of  claim 17 , wherein outflow diversion means is located at or near the exit region of the spacings defining the first fluid flow path, to enhance uniformity of flow out of said first fluid flow path.  
   
   
       20 . The heat exchanger of  claim 1 , wherein the plates are also connected to at least one of the first and second headers by respective support members.  
   
   
       21 . The heat exchanger of  claim 20 , wherein at least one of the support members comprises jointing means allowing relative movement between the headers and the plates.  
   
   
       22 . The heat exchanger of  claim 21 , wherein the jointing means allow the movement to occur with at least one degree of freedom.  
   
   
       23 . The heat exchanger of  claim 1 , wherein at least one pusher bar connects the first and second headers.  
   
   
       24 . The heat exchanger of  claim 23 , wherein the or each pusher bar has a hinge connection to least one of said first and second headers.  
   
   
       25 . The heat exchanger of  claim 1 , wherein the first header is connected to a source of the first fluid, means being provided for feeding the second fluid from a source of the second fluid to the second fluid flow path, wherein the first fluid at source has a pressure equal to or greater than that of the second fluid at source.  
   
   
       26 . The heat exchanger of  claim 1 , wherein the plates are substantially flat.  
   
   
       27 . The heat exchanger of  claim 26 , wherein the plates are substantially parallel to each other and the stack is substantially cubic or rectangular.  
   
   
       28 . The heat exchanger of  claim 26 , wherein the plates are arranged in radial fashion.  
   
   
       29 . The heat exchanger of  claim 1 , wherein the plates are curved and in substantially involute arrangement.  
   
   
       30 . The heat exchanger of  claim 1 , wherein the plates are provided with surface projections for enhancing heat transfer.  
   
   
       31 . The heat exchanger of  claim 30 , wherein the plates are arranged in a plurality of groups each comprising at least two plates, the surface projections being in the form of a plurality of groups of pins, the pins in each group being arranged to bridge plates of a respective plate group.  
   
   
       32 . The heat exchanger of  claim 31 , wherein the groups of plates are pairs of plates and the spacings between the plates of each pair constitute the first fluid flow path.  
   
   
       33 . A heat exchanger comprising a stack of mutually spaced apart plates separated by respective spacings therebetween, wherein alternate spacings respectively provide a flow path for a first fluid and a second fluid, the heat exchanger further comprising a first header for inflow of the first fluid and a second header for outflow of the first fluid, the first and second headers being connected to the plate stack by tubular ducting means, wherein the plates are flat and are arranged in radial fashion.  
   
   
       34 . The heat exchanger of  claim 33 , wherein the tubular ducting means comprises respective tubes communicating between the spacings representing the first fluid flow path and the inside of the first and second headers.  
   
   
       35 . A heat exchanger comprising a stack of mutually spaced apart plates separated by respective spacings therebetween, wherein alternate spacings respectively provide a flow path for a first fluid and a second fluid, the heat exchanger further comprising a first header for inflow of the first fluid and a second header for outflow of the first fluid, the first and second headers being connected to the plate stack by tubular ducting means, wherein the plates are curved and in substantially involute arrangement.  
   
   
       36 . The heat exchanger of  claim 35 , wherein the tubular ducting means comprises respective tubes communicating between the spacings representing the first fluid flow path and the inside of the first and second headers.